1. Field of the Invention
The present invention relates to a water cut-off inspection device for inspecting whether a watertight seal is achieved in the gap between bundled electric wires that have been inserted into a grommet.
2. Description of the Related Art
Electric wires are bundled and passed through a through-hole formed in a partitioning wall between an engine compartment and a passenger or storage compartment of a vehicle. The bundled electric wires are used with a grommet that has a through opening and an outwardly extending flange. More particularly, the bundled electric wires are inserted through the through opening provided in the grommet and the flange is engaged with the periphery of the through-hole in the partitioning wall. A resinous material is filled into the gap between the electric wires accommodated in the grommet to achieve a watertight seal of the gap between the electric wires. The prior art has not included means for inspecting whether the gap between the electric wires has achieved a sufficiently watertight seal.
The present invention has been made in view of the above-described situation. Thus, it is an object of the present invention to provide an inspection device for inspecting whether the gap between the front side of a grommet and the rear side thereof has achieved a watertight seal.
The present invention is directed to an inspection device for inspecting whether the gap between bundled electric wires that have been inserted into a grommet has a watertight seal. The inspection device includes a cylindrical member, and the electric wires that project from a front end of the grommet are inserted into the cylindrical member. The inspection device also includes a sealing means for sealing the cylindrical member. A supply of air then is supplied into the cylindrical member, and a test is performed to determine whether a flow of the pressurized air exists across the grommet. When air supplied into the cylindrical member stops due to pressurization, it is determined that the grommet has passed an examination.
The inspection device utilizes the fact that when an air pressure inside the cylindrical member reaches a steady state, additional air does not flow into the cylindrical member if a gap between the electric wires is sealed securely. On the other hand, air continues to flow into the cylindrical member if there is a gap between the electric wires.
Preferably, the sealing means of the cylindrical member includes a cover that has an electric wire insertion hole and a grommet-holding frame that can be fitted on the front end of the grommet. The grommet-holding frame is brought close to the cylindrical member with a catching fitting to press a surface of the front end of the grommet against the cover. The interior of the cylindrical member can be accessed by opening the cover. Electric wires then can be inserted easily into the cylindrical member, with connectors mounted on the electric wires. Thus, the grommet-holding frame can be installed on the cylindrical member with the cover closed, and it is possible to prevent leakage of the air inside the cylindrical member.
Preferably, the cover is composed of two parts; and the electric wire insertion hole straddles the two parts. In this construction, the electric wire insertion hole is open, and hence the electric wires and the connectors provided thereon can be inserted easily into the insertion hole.
A packing preferably is formed on a periphery of an open portion of the cylindrical member. It is also preferable to form a groove on the cover into which the packing can be fitted. This construction improves the sealing performance of the cylindrical member.
An elastic member preferably is interposed between the grommet-holding frame and the cover. Thus, it is possible to facilitate a removing operation.
The grommet-holding frame preferably has a press rib fitted in an annular groove formed on a periphery of the front end of the grommet to sandwich a front edge portion of the grommet formed forward from the annular groove between the cover and the press rib. In this case, it is possible to seal the grommet during an inspecting operation by reliably sandwiching the front edge portion between the press rib and the cover.
Preferably, the grommet-holding frame is connected removably to the cylindrical member as a unit. In this case, the installation and removal of the sealing means can be accomplished easily during the installation of the grommet on the cylindrical member even if the wires that project from the grommet are connected with connectors.
In another aspect of the present invention, there is provided a holder for holding the unit of the grommet-holding frame and the cover temporarily. Thus, the grommet is installed on the grommet-holding frame that is accommodated in an accommodation portion. The unit can be installed on and removed from the holder and the grommet is removed from the grommet-holding frame. In this case, it is very easy to install the grommet on the cylindrical member.